They may be. It just sticks in my mind that some vehicles in the 80's and 90's had a service interval light that was different from the CEL. Could be wrong though.Maybe it is check engine- I never realized they were different things- in my mind they were one the same.
Yes, they did. However, "Service engine soon" and "check engine" are typically both referring to the malfunction indicator light.They may be. It just sticks in my mind that some vehicles in the 80's and 90's had a service interval light that was different from the CEL. Could be wrong though.
Seems to run OK otherwise... Anyway to figure out what 45 is?How does it run otherwise?
With it kicking out code 21, I'd put an oxygen sensor in it, clear the codes, and drive it.
Not sure what 45 is... according to allpar: 1980s Chrysler, Plymouth, and Dodge computer fault codes it's 45 Turbo boost limit exceeded (engine was shut down by logic module)Seems to run OK otherwise... Anyway to figure out what 45 is?
When you say put an oxygen sensor in it, you mean, replace the one that is there?
Definitely possibile, but O2 sensors are exceedingly common Chrysler failures. I've done at least one on each chryco vehicle I've owned. If it's throwing the 21 code, I'd replace it if it hasn't been done in awhile regardless of any other codes.If the 17 code is legit, you might be getting an O2 sensor code as a result of the engine not getting up to temp. Would be odd, for sure, but possible.
A bad O2 sensor can be completely asymptomatic other than tossing a CEL.It can run okay with a bad O2 sensor, it will just guzzle fuel.
Agreed. They're relatively easy to replace. Ditto on checking for burnt wires, but even then, it may be easier just to replace. I think I've replaced the ones on my TJ about 4-5x in the ~230k miles I've driven it.Definitely possibile, but O2 sensors are exceedingly common Chrysler failures. I've done at least one on each chryco vehicle I've owned. If it's throwing the 21 code, I'd replace it if it hasn't been done in awhile regardless of any other codes.
Not a bad idea. As I mentioned before, I have an OBD suite on my laptop which can monitor the voltage from O2 sensors. I've used it before for specifically this purpose on a Neon. The downstream sensor was outputting a nice constant voltage within spec. The upstream was super erratic. Told the owner "replace the upstream one." Handy as hellI also always pull the O2 sensor and bench test it before I replace it since the old Chryco shit doesn't always accurately denote which sensor is bad. Bench test = propane torch and multimeter. I usually hit it with a MAPP torch first to burn out any fouling.
I havent found a mobile app that will drill down to O2 sensor voltage. I cant think of any reason your TJ wouldn't give you that reading.I just have Torque and a BT scan tool. I don't think my TJ gives me voltage from the O2 sensors. Could be wrong though.